Photoinduced behavior of charge density wave in YBa<sub>2</sub>Cu<sub>3</sub>O<sub>6.67</sub> : Bridging the gap between equilibrium and nonequilibrium normal states in high-T<sub>c</sub> cuprates
ORAL
Abstract
In cuprate superconductors, charge density wave (CDW) has been ubiquitously observed, particularly by X-ray scattering technique, and investigated as an important aspect in normal state. To study the normal state of the cuprates at low temperature below Tc, the superconductivity has been suppressed by applying either an external magnetic field or an optical pump laser. Those excitations respectively induce equilibrium or nonequilibrium normal state. The development of high intense, ultrashort pulsed X-ray sources, i.e. X-ray free electron lasers, opens another chapter of the CDW studies, e.g. discovery of three-dimensional (3D) CDW and characterization of transient behaviors. In this talk, we present the transient behavior of CDW in YBa2Cu3O6.67. We utilized 800 nm (1.55 eV) optical laser pump and Cu L3-edge (932 eV) X-ray probe for time-resolved resonant elastic soft X-ray scattering. Below Tc, the suppression of superconductivity enhances CDW intensities within a few ps. We further observed out-of-plane correlation changes, which resemble field-induced 3D precursor correlation. Ultimately, we discuss that a transient normal state triggered by the laser-driven quench of the superconducting state is possible to represent phenomena of the equilibrium state.
*This work is supported by US DOE (DE-AC02-76SF00515), Korea MSIT (PAL-XFEL and 2019R1F1A1060295), Japan (KAKENHI 19H00647).
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Publication: H. Jang, S. Song et al. Sci. Adv. 8, eabk0832 (2022)
Presenters
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Hoyoung Jang
- Pohang Accelerator Laboratory